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$529+ Cheap flights from London (LON) to Seattle (SEA)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 7/31. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
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Cheapflights Tip: The best prices from London to Seattle/Tacoma Intl are usually found in January or March, booked 43 days in advance, depart on a Wednesday or Thursday and return on a Tuesday

Cheap flight deals from London to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from London (LON) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated June 12, 2025.

Round-trip from

$646
(Cheapflightsfares)

One-way from

$529
(Mytrip)

Popular in

August

Cheapest in

January

Average price

$757

Good round-trip deal

$668 or less

Good one-way deal

$621 or less
From London (LON) to Seattle/Tacoma Intl
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One-way flight from London (LON) to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 15% potential increase in price ($140 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($23 potential savings vs. average RT price).
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Average for round-trip flights in June 2025
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Price to beat on a round-trip flight from London (LON) to Seattle/Tacoma Intl.
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Price to beat on a one-way flight from London (LON) to Seattle/Tacoma Intl.
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Find flight deals from London to Seattle

Cheapest flights from London to Seattle
Explore the most affordable flight options available from London to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 12, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/104:30 pmLHR - SEA
Nonstop9h 50mBritish Airways
Sun 9/148:20 pmSEA - LHR
Nonstop9h 20mBritish Airways
Deal found 6/11$646
This Bravofly deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Bravofly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/103:40 pmLGW - SEA
1 stop13h 00mIcelandair
Thu 7/2411:30 pmSEA - LGW
1 stop28h 15mIcelandair
Deal found 6/11$647
This TravelUp deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure TravelUp is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/176:30 amLHR - SEA
1 stop13h 10mKLM
Tue 6/241:55 pmSEA - LHR
1 stop12h 50mKLM
Deal found 6/10$647
This Booking.com deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/96:15 amLHR - SEA
1 stop13h 00mVirgin Atlantic
Tue 7/225:35 pmSEA - LHR
Nonstop9h 45mVirgin Atlantic
Deal found 6/12$649
This Delta deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/3111:45 amLHR - SEA
1 stop32h 00mDelta
Mon 9/88:25 pmSEA - LHR
Nonstop9h 50mDelta
Deal found 6/11$652
This The Travel House deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/16:40 amLHR - SEA
1 stop15h 20mScandinavian Airlines
Wed 10/2912:00 pmSEA - LHR
2 stops45h 00mScandinavian Airlines
Deal found 6/10$653
This Gotogate deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/99:25 pmLHR - SEA
1 stop22h 00mIcelandair
Mon 7/2111:30 pmSEA - LHR
1 stop28h 25mIcelandair
Deal found 6/12$654
This SWISS deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure SWISS is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/291:30 pmLCY - SEA
2 stops40h 45mSWISS
Sat 11/153:37 pmSEA - LCY
2 stops17h 28mSWISS
Deal found 6/12$655
This American Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/181:10 pmLHR - SEA
1 stop14h 52mAmerican Airlines
Thu 9/111:07 pmSEA - LHR
1 stop15h 08mAmerican Airlines
Deal found 6/10$656
This Mytrip deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/225:05 pmSTN - SEA
3 stops28h 45mMultiple Airlines
Sat 8/304:00 pmSEA - STN
2 stops24h 20mMultiple Airlines
Deal found 6/12$660
This Air Canada deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/227:30 amLHR - SEA
2 stops19h 06mMultiple Airlines
Sun 9/145:30 amSEA - LHR
2 stops17h 00mMultiple Airlines
Deal found 6/12$662
This Air Canada deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/108:40 amLHR - SEA
2 stops18h 51mAir Canada
Sun 9/145:30 amSEA - LHR
2 stops17h 00mAir Canada
Deal found 6/11$665

Cheapflights Fare Finder

Customize your flight search to find flights from London to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

London

Fly to

Seattle

Route

Depart

Return

Price

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 9/10

4:30 pm-6:20 pm

Nonstop9h 50m

Seattle/Tacoma Intl

Sun 9/14

8:20 pm-1:40 pm

Nonstop9h 20m

$646

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Thu 7/10

3:40 pm-8:40 pm

1 stop13h 00m

Seattle/Tacoma Intl

Thu 7/24

11:30 pm-11:45 am

1 stop28h 15m

$647

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 7/9

9:00 am-5:25 pm

1 stop16h 25m

Seattle/Tacoma Intl

Wed 7/16

8:25 pm-2:15 pm

Nonstop9h 50m

$647

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 7/9

6:15 am-11:15 am

1 stop13h 00m

Seattle/Tacoma Intl

Tue 7/22

5:35 pm-11:20 am

Nonstop9h 45m

$649

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Sun 8/31

11:45 am-11:45 am

1 stop32h 00m

Seattle/Tacoma Intl

Mon 9/8

8:25 pm-2:15 pm

Nonstop9h 50m

$652

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 10/1

6:40 am-2:00 pm

1 stop15h 20m

Seattle/Tacoma Intl

Wed 10/29

12:00 pm-4:00 pm

2 stops45h 00m

$653

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 7/9

9:25 pm-11:25 am

1 stop22h 00m

Seattle/Tacoma Intl

Mon 7/21

11:30 pm-11:55 am

1 stop28h 25m

$654

LondonSeattle

LCY - SEA

LCYSEA

London City

Wed 10/29

1:30 pm-11:15 pm

2 stops40h 45m

Seattle/Tacoma Intl

Sat 11/15

3:37 pm-5:05 pm

2 stops17h 28m

$655

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 8/18

1:10 pm-8:02 pm

1 stop14h 52m

Seattle/Tacoma Intl

Thu 9/11

1:07 pm-12:15 pm

1 stop15h 08m

$656

LondonSeattle

STN - SEA

STNSEA

London Stansted

Fri 8/22

5:05 pm-1:50 pm

3 stops28h 45m

Seattle/Tacoma Intl

Sat 8/30

4:00 pm-12:20 am

2 stops24h 20m

$660

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/11

Showing 1-10 of 52 results
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The best insider tips for London to Seattle flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your London to Seattle trip
Airports
LHR

For a smooth departure from Heathrow, ensure all liquids are in one small bag to avoid lengthy security checks.

Read more about LHRby Ramsey Qubein
SEA

Use the Link light rail from SEA to downtown Seattle for an affordable, 40-minute journey with ample luggage space.

Read more about SEAby Brandon Schultz
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on LHR

Ramsey Qubein

Ramsey Qubein

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

Best time to book a flight from London to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from London with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from London to Seattle

How far ahead should I book a flight from London to Seattle?

Use this chart to determine the optimal time to book a round-trip flight from London to Seattle. Price data was last updated on June 9, 2025.

To ensure you get the cheapest price possible for a flight from London to Seattle, you should look to book at least 43 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from London to Seattle?

Currently, January is the cheapest month in which you can book a flight from London to Seattle (average of $238). Flying from London to Seattle in July is currently the most expensive (average of $391). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from LON to SEA?

Find hourly flight availability from London to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated June 12, 2025.

One of the essential ways to save on airfare from London to Seattle is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 12% on airfare.

What is the cheapest day to fly from London to Seattle?

Use this chart to determine the cheapest time to fly round-trip from London to Seattle. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their London to Seattle flight should consider departing on Monday evenings when fares are most often at their lowest. Friday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from London to Seattle

Explore weekly flight availability from London to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated June 12, 2025.

The most flights from LON to SEA are scheduled on a Monday (22 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (11 on average).

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated June 12, 2025.
Peruse reviews from past customers who have flown with Delta, KLM and Finnair from London to Seattle to help guide your decision. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Entertainment

7.9

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Delta
8.0
Very good
7,950 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Entertainment

7.9

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
KLM
7.8
Good
1,358 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Entertainment

7.9

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Finnair
7.6
Good
1,290 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Entertainment

7.9

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Air France
7.5
Good
1,463 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Entertainment

7.9

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
SWISS
7.5
Good
1,623 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Entertainment

7.9

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Related info for your journey

Find useful and relevant information for your journey from London to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from London?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from London to Seattle. 6 airlines have flights to Seattle/Tacoma Intl from London on a regular basis. Booking flights from London to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 18 inbound flights from London per day.

  • What are the cheapest airlines flying from London to Seattle round-trip?

    Cheapflights users have booked flights from London to Seattle round-trip from $646. Other airlines that can offer you cheap pricing are Icelandair, from $647, and KLM, from $647. British Airways is currently priced 14% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from London to Seattle one-way?

    One-way options have recently been found by users for as low as $532 on Aer Lingus. Other airlines that offer cheap prices include WestJet from $541 and Scandinavian Airlines from $609 one-way.

  • What are the most popular routes from London to Seattle?

    Most travelers choose London Heathrow - Seattle/Tacoma Intl, London Gatwick - Seattle/Tacoma Intl or London City - Seattle/Tacoma Intl when deciding on the best route from London to Seattle.

  • What are the most reliable airlines from London to Seattle?

    The top 3 most reliable airlines when flying from London to Seattle are Aeromexico (97%), KLM (92%) and Air France (92%).

  • What are the cheapest flights from London to Seattle?

    While on average a flight from London to Seattle is generally $2,306, our data shows the cheapest flight currently is $532. When looking at the most popular route, (London Heathrow - Seattle/Tacoma Intl), you can expect to pay $318 for that flight.

  • Can I find deals for flights from London to Seattle that include hotel bookings?

    Yes. In addition to deals on London to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from London to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Seattle.

  • Can I find deals for business class flights from London to Seattle?

    Yes. Cheapflights offers flight deals from London to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from London to Seattle?

    Currently, January is the cheapest month in which you can book a flight from London to Seattle (average of $238). Flying from London to Seattle in July is currently the most expensive (average of $391). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
SeaTac
Tukwila
Tacoma
Lakewood
Ocean Shores
Lacey
Leavenworth
Federal Way
Lynnwood
Olympia
Shoreline
Kent
Cle Elum
Centralia
Kirkland
Aberdeen
Renton
Shelton
Silverdale
Issaquah

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Alternative routes for London to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from London to Seattle

Discover the top 6 airlines that operate flights from London to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest$402Average$792FlexibilityNo cancel feeOn-time76%
British AirwaysCheapest$560Average$763FlexibilityNo cancel feeOn-time70%
IberiaCheapest$575Average$1,001FlexibilityNo cancel feeOn-time77%
Virgin AtlanticCheapest$594Average$941FlexibilityNo cancel feeOn-time72%
American AirlinesCheapest$620Average$889FlexibilityNo cancel feeOn-time71%
DeltaCheapest$632Average$887FlexibilityNo cancel feeOn-timeN/A

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